1. Field of the Invention
The present invention relates to an automotive alternator that is mounted to a vehicle, and particularly relates to a construction that cools a voltage regulator.
2. Description of the Related Art
In conventional automotive alternators, a rectifier assembly is configured into an approximate C shape, and a voltage regulator, a brush holder, and a connector are configured integrally into a regulator assembly. The voltage regulator and the brush holder are disposed so as to overlap in an axial direction of a shaft, and the connector is disposed at a position that is rotated by a predetermined angle circumferentially from the voltage regulator and the brush holder in a plane that is perpendicular to the shaft and that includes the voltage regulator and the brush holder such that an opening portion faces radially outward. The regulator assembly is disposed in a space in an opening portion of the C shape of the rectifier assembly. Thus, the size of the heatsink of the rectifier is limited by the regulator assembly and cannot be enlarged. Furthermore, ventilation resistance in the connector and ventilation resistance in the voltage regulator differ from each other, and irregularities in ventilation resistance on an intake side that includes the rectifier assembly are great.
In view of these conditions, improved conventional automotive alternators have been proposed that include a regulator assembly in which a voltage regulator and a brush holder are disposed so as to overlap in an axial direction of a shaft, and the connector is disposed in close contact with the voltage regulator radially outside the voltage regulator such that an opening portion faces radially outward (see Patent Literature 1, for example). In these improved conventional automotive alternators, because the regulator assembly is disposed in a space in an opening portion of the rectifier assembly that has a C shape, the heatsink of the rectifier can be made larger, improving cooling of the rectifier. In addition, irregularities in ventilation resistance on the air intake side that includes the rectifier assembly are reduced.
Patent Literature 1: Japanese Patent Laid-Open No. 2002-142423 (Gazette), which corresponds to U.S. Pat. No. 6,740,995 to Oohashi et al.
In improved conventional automotive alternators, the connector is disposed radially outside the voltage regulator in order to improve cooling of the rectifier. The heatsink of the voltage regulator is disposed in a plane that is perpendicular to the shaft such that ventilation channels between the fins are aligned in a radial direction. The connector is placed in close contact with a radially outer side surface of the heatsink of the voltage regulator, and is in a state that blocks radially outer openings of the ventilation channels between the fins. Thus, cooling air does not flow into the ventilation channels between the fins of the heatsink of the voltage regulator satisfactorily, making cooling performance of the heatsink poor and increasing the temperature of the voltage regulator.